hyposulphurous, a. [Pref. hypo- + sulphurous.].
Pertaining to, or containing, sulphur, all, or a part, in a low state of oxidation. [1913 Webster]
Hyposulphurous acid.
(a) Thiosulphuric acid. [Obs.] (b) An acid, H2SO2, obtained by the reduction of sulphurous acid. It is not obtained in the free state, but in an orange-yellow water solution, which is a strong reducing and bleaching agent. Called also hydrosulphurous acid.